I just printed some 16x16 prints from a box of Ilford MGIV Fiber that is about 5 years old. As far as I know, it has been at room temperature, but moved around. It behaved just as I thought it would, even very close scaling up exposures and filtration to a new box of 8x10 RC. However, most of the edges have a very soft, mostly very light yellowish tint in the borders (1/2 inch), worst at the outside edge, feathering off before hitting the image, luckily. It's not on every print, and not on every edge, probably 20% of the edges.
Developed in Ethol LPD 1:2 for 2 minutes, water stop for a minute in slow running water, TF4 fix, 45 seconds in each of 2 baths, the first used some, but working, the second fresh. Re-rinse again in water, Gravity Works wash for an hour or so. The water temp throughout was around 80F, chems at about 75 room temp.
I've heard of this before, but never had it happen to me. I think I can use them, I'll know after matting, and I can increase the border on other prints later in the box, but if it's something I'm doing, I'd like to know.
The other question - I have had 2 boxes of Ilford MG fiber, not IV, given to me, unopened. According to the donor, they've been in a freezer. One has the same picture as the current packaging (tree and animals) but a different label, and one has an old image of a rail yard. How will this paper be different from the current stuff? If it is known to be no where near as good, I might donate it to a school.